Art. 55. The transfer of an enemy vessel to a neutral flag, effected before the outbreak of hostilities, is valid, unless it is proved that such transfer was made in order to evade the consequences to which an enemy vessel, as such, is exposed. There is, however, a presumption, if the bill of sale is not on board a vessel which has lost her belligerent nationality less than sixty days before the outbreak of hostilities, that the transfer is void. This presumption may be rebutted. Where the transfer was effected more than thirty days before the outbreak of hostilities, there is an absolute presumption that it is valid if it is unconditional, complete, and in conformity with the laws of the countries concerned, and if its effect is such that neither the control of, nor the profits arising from the employment of the vessel remain in the same hands as before the transfer. If, however, the vessel lost her belligerent nationality less than sixty days before the outbreak of hostilities and if the bill of sale is not on board, the capture of the vessel gives no right to damages.